In a high-voltage or ultra-high voltage cable connection system, such as a connection system with a voltage level of 66 KV or more, it is necessary to install an insulation termination assembly on a joint of the cable to electrically connect, for example, a high voltage cable and an overhead line. The insulation termination assembly generally comprises an insulation tube, an insulation umbrella skirt, a metal flange, and a conductive rod led out of an end of the insulation tube. The insulation tube is filled with an insulation oil. The cable is partly stripped at a connection end thereof to form a cable joint. The cable joint is received in the insulation tube. The insulation umbrella skirt is formed on an outer wall of the insulation tube. The metal flange is attached to a base of the insulation tube.
A plurality of support insulators are commonly pre-installed on the metal flange. The support insulators increase the size of the metal flange and complicate the structure of the insulation termination assembly, increasing the cost of the metal flange and the cost of the insulation termination assembly as a whole.